A urethane is produced by reacting an organic nitro compound with carbon monoxide and an organic compound containing at least one hydroxyl group in the presence of a catalyst and a co-catalyst. This reaction is conducted in the liquid phase at elevated temperature and pressure. The catalyst employed is an element and/or compound of an element from the group of noble metals of the 8th Secondary Group of the Periodic Table. The co-catalyst used is formed from (1) a component taken from the group consisting of iron oxychloride, a mixture of iron compounds containing iron oxychloride and oxide-chloride combinations and (2) metallic iron or an iron alloy in finely divided or high surface form. The oxides which may be used in the oxide-chloride combinations of co-catalyst component (1) are the oxides and/or oxide hydrates of tetravalent tin, trivalent chromium, hexavalent molybdenum, hexavalent tungsten, pentavalent vanadium, divalent iron and trivalent iron. The chlorides which may be used in this oxide-chloride combination are chlorides of the elements of Groups IIIA, IVA, VA and IB to VIIIB of the Periodic Table and/or hydrochlorides of tertiary amines.